Luna and Isabella are stepsisters who became family through their parents' remarriage.

Unlike Luna, who wished to get along as a family, Isabella inexplicably views Luna as an enemy and begins to harass her.

However, her harassment was insidious. She dresses in clothes so plain one wouldn't expect from a high-ranking noble, and proclaims, "I'm being tormented by my stepmother and stepsister…"

The people who are swayed by Isabella's words, and their fate.